Engine modifications, What makes the best sense ? |
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Engine modifications, What makes the best sense ? |
jim_hoyland |
Jul 2 2016, 07:42 PM
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#1
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Get that VIN ? Group: Members Posts: 9,418 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
About 10 years ago my stock '75 1.8L L-Jet was rebuilt. A 2L crank was installed along with 94mm pistons.
Can runs good, slows down quite a bit on hills. My mechanic has suggested replacing the cylinders/Pistons with 96mm. The engine would be kept FI with the L-Jet Does this make sense and would other mods be required ? |
Mark Henry |
Jul 2 2016, 08:43 PM
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#2
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
96mm over 94mm won't make a difference, at least not noticeable.
I wouldn't change unless you need new P&Cs. L-jet is what it is, smooth running, predictable, but it's not a powerhouse. The only cheap mod that will make good, noticeable improvement is a set of headers...but then you will lose heat. |
colingreene |
Jul 2 2016, 08:50 PM
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#3
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Senior Member Group: Members Posts: 730 Joined: 17-October 13 From: Southern California Member No.: 16,526 Region Association: Southern California |
Jim lives in Sunset beach, really no need for heat.
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wndsrfr |
Jul 2 2016, 08:54 PM
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#4
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Senior Member Group: Members Posts: 1,436 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
About 10 years ago my stock '75 1.8L L-Jet was rebuilt. A 2L crank was installed along with 94mm pistons. Can runs good, slows down quite a bit on hills. My mechanic has suggested replacing the cylinders/Pistons with 96mm. The engine would be kept FI with the L-Jet Does this make sense and would other mods be required ? Your current cylinders can be bored & honed to fit 96mm pistons....they're likely better quality and certainly more thermally stable than new ones would be.... |
jim_hoyland |
Jul 2 2016, 08:57 PM
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#5
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Get that VIN ? Group: Members Posts: 9,418 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
Thanks for that analysis, you pretty much said what I have read over the years. A local here, with a L-Jet like mine, installed the Tangerine headers and it seemed to have made a nice improvement.
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ClayPerrine |
Jul 2 2016, 08:57 PM
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#6
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Life's been good to me so far..... Group: Admin Posts: 15,820 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille |
L-jet is what it is, smooth running, predictable, but it's not a powerhouse. I disagree. The L-Jet on Betty's 914 is great. It is smooth and reliable. And it is the basis for the Motronic system used on all current Porsche cars. The biggest problem with a stock motor is breathing. Bigger valves, a different cam, and a bigger throttle body does wonders for a 914 with L-Jet. I put a Raby 9590 cam in Betty's car, along with 2.0 valves in 1.8 heads and a Bus throttle body. Doing that woke up the motor. It pulls strong all the way to redline. |
jim_hoyland |
Jul 2 2016, 09:34 PM
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#7
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Get that VIN ? Group: Members Posts: 9,418 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
L-jet is what it is, smooth running, predictable, but it's not a powerhouse. I disagree. The L-Jet on Betty's 914 is great. It is smooth and reliable. And it is the basis for the Motronic system used on all current Porsche cars. The biggest problem with a stock motor is breathing. Bigger valves, a different cam, and a bigger throttle body does wonders for a 914 with L-Jet. I put a Raby 9590 cam in Betty's car, along with 2.0 valves in 1.8 heads and a Bus throttle body. Doing that woke up the motor. It pulls strong all the way to redline. Are the 2.0 valves direct replacements, or does other work need to e done on the head.? |
r_towle |
Jul 2 2016, 09:43 PM
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#8
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Custom Member Group: Members Posts: 24,624 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
In my opinion, like a computer, it's possible that it seems slower....
I would suggest you do two things, both are in your quest to solve the problem, but will provide you with a fun summer. First, run some simple water through the engin while it's running. Use the 1/8 vacuum advance hose for the distributor while its warmed up Slowly run about a liter of water though the engine, outdoors. It will steam clean th Carbon out, so there will be lots of smoke... Then give it a tune up. Second, Find a core motor and build a 2270 to get more power as you want. Mark could do it, or EMW could do it...or FAT... Rich |
Mark Henry |
Jul 2 2016, 09:53 PM
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#9
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
L-jet is what it is, smooth running, predictable, but it's not a powerhouse. I disagree. The L-Jet on Betty's 914 is great. It is smooth and reliable. And it is the basis for the Motronic system used on all current Porsche cars. The biggest problem with a stock motor is breathing. Bigger valves, a different cam, and a bigger throttle body does wonders for a 914 with L-Jet. I put a Raby 9590 cam in Betty's car, along with 2.0 valves in 1.8 heads and a Bus throttle body. Doing that woke up the motor. It pulls strong all the way to redline. I don't mean that in a bad way, I have a 914 2.0 with L-jet here and it's every bit as powerful as a D-jet. In fact it's a hoot, may be the kick in the pants I needed to get my 3.0 914 finished. I'm also biased as I've never driven a stock engined aircooled anything, at least not for very long. I guess driving a 180hp 2.6L T4 in a 1700lb VW bug has me a tad spoiled. (IMG:style_emoticons/default/biggrin.gif) Are the 2.0 valves direct replacements, or does other work need to e done on the head.? You would have to replace the seats. I'd get real 2.0 heads and do a straight swap. Still not anywhere near the gain of a set of headers. |
Mueller |
Jul 2 2016, 10:57 PM
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#10
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914 Freak! Group: Members Posts: 17,150 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
Hi Jim, I thought when I drove your car last year at the WCR it pinged a bit while going up a few of the hills.
No input on a motor build, doing one right now so I'll keep an eye on what others suggest. |
914forme |
Jul 3 2016, 06:14 AM
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#11
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Times a wastin', get wrenchin'! Group: Members Posts: 3,896 Joined: 24-July 04 From: Dayton, Ohio Member No.: 2,388 Region Association: None |
Tangerine Headers - you can keep heat heat if that is a requirement. Chris does great work and the only Issue I see with these works of art is, you want to put a mirror under your car, and keep it on jack stands. :drooled:
For your sanity, clean everything up, take a picture, poster size it hang it on the wall and (IMG:style_emoticons/default/driving.gif) After that, I would suggest a cam, Heads, the 1.8L are pretty good, with some work done to them. And L-Jet is not a bad system. Ran one on a 1911 motor, loved that -4 it would spin up fast, great little auto-x motor, not bad on the street. L-Jet, Mallory, and a set of Kerry Hunter Headers, switched to european Racing, which where better, made my last switch to Mr. Foley's headers and never looked back. Get them well worth the $$$$. That being said, I would ITB the motor and run and EFI system on the car. Header Cam Bigger Valves EFI and Ignition Dub Shop EFI |
jim_hoyland |
Jul 3 2016, 06:29 AM
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#12
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Get that VIN ? Group: Members Posts: 9,418 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
Hi Jim, I thought when I drove your car last year at the WCR it pinged a bit while going up a few of the hills. No input on a motor build, doing one right now so I'll keep an eye on what others suggest. I remember that; interestingly that was the only time that occurred. The recent drive to Flagstaff was ping-free and there was similiar opportunities. I do have the Mallory Uni Lite installed and a pair of 1.8 heads coming after Fat Performance resurfaces them and cleans them up Lots of terrific suggestions....really appreciate (IMG:style_emoticons/default/smile.gif) |
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